JP4456952B2 - Electrophotographic photosensitive member, process cartridge, and electrophotographic apparatus - Google Patents

Description

  The present invention relates to an electrophotographic photosensitive member used for electrophotographic image formation, and a process cartridge and an electrophotographic apparatus using the electrophotographic photosensitive member.

  The electrophotographic system is used in electrophotographic apparatuses such as copying machines and laser beam printers because it can obtain high-quality printing at high speed.

  As an electrophotographic photosensitive member used in an electrophotographic apparatus, an organic electrophotographic photosensitive member using an organic photoconductive material has become the mainstream, and the configuration of the electrophotographic photosensitive member includes a charge transport material and a charge generating material. The performance has been improved by changing to a function-separated type electrophotographic photosensitive member dispersed in a separate layer.

  In the case of this function-separated type electrophotographic photoreceptor, at present, an undercoat layer is first formed on an aluminum substrate, and then a photosensitive layer comprising a charge generation layer and a charge transport layer is often formed.

  Regarding the improvement of stability and environmental stability of electrophotographic photoreceptors when used repeatedly, there are many parts that depend not only on the charge generation layer and charge transport layer but also on the subbing layer, so that the charge storage property due to repeated use is low. Subtraction is required.

  In addition, the undercoat layer plays a major role in preventing image quality defects, and the undercoat layer is important in order to suppress image quality defects caused by defects or unevenness in the upper layer such as substrate defects and dirt or charge generation layers. It is a functional layer.

  In particular, in recent years, contact charging type charging devices that generate less ozone instead of corotron have been used in electrophotographic devices, and the electrical degradation is caused by a local high electric field applied to the locally deteriorated portion of the electrophotographic photosensitive member during contact charging. In some cases, a pinhole is generated, resulting in an image quality defect.

  This pinhole leak may occur due to a coating film defect of the electrophotographic photosensitive member itself, but otherwise, conductive foreign matter generated from the inside of the electrophotographic apparatus is brought into contact with the electrophotographic photosensitive member or the electrophotographic photosensitive member. This occurs because it easily penetrates into the body and forms a conductive path between the contact charging device and the electrophotographic photosensitive member substrate. In a noticeable case, foreign matter mixed from other members in the electrophotographic apparatus or dust mixed in the electrophotographic apparatus may pierce the electrophotographic photosensitive member to form a leak point from the contact charging device.

  For such a problem, a layer containing a conductive fine powder is applied and formed on the substrate in order to conceal the defects of the substrate by thickening the undercoat layer and to obtain stability in electrical characteristics. Methods have been taken so far.

  One of them is a method in which a conductive powder-dispersed conductive layer is formed on an aluminum substrate, and an undercoat layer is formed thereon. In this case, the base material is concealed by the conductive layer and the resistance is adjusted, and the blocking (charge injection control) function is provided by the undercoat layer.

  As another method, a conductive powder dispersion layer having both a blocking (charge injection control) function and a resistance adjustment function is applied on the substrate, and the functions of the blocking (charge injection control) layer and the resistance adjustment layer are applied. It is a method used as an undercoat layer having both.

  Compared with the former undercoating layer method, the latter undercoating layer requires one fewer layers, so that the manufacturing process of the electrophotographic photosensitive member can be simplified and the cost can be reduced.

  However, in the case of the latter undercoat layer, it is necessary to incorporate the resistance control function and the charge injection control function into one undercoat layer, which has a great limitation in material design.

  From the viewpoint of preventing leakage, the thicker the undercoat layer, the greater the effect. A film thickness of 10 μm or more is required. However, when the film thickness is increased, it is necessary to reduce the resistance in order to obtain good electrical characteristics. In such a case, the charge blocking property is weakened, and the fog as an image quality defect tends to increase.

  The film thickness of the latter undercoat layer, which has been put into practical use using titanium oxide conductive powder, has been limited to the range of about 1 to several μm. There was no subbing layer capable of satisfying all the characteristic values required for an electrophotographic photosensitive member such as improvement in leakiness, stabilization of electric characteristics and fog.

  In particular, in recent years, expectations for development of a long-life electrophotographic photosensitive member have increased due to increasing awareness of environmental problems, and it has become essential to improve the stability of electrical characteristics and image quality during repeated use over a long period of time.

Further, a method for adding an additive such as an electron accepting substance or an electron transporting substance to the undercoat layer has been proposed. (For example, see Patent Documents 1 to 3)
JP 7-175249 A JP-A-8-44097 JP-A-9-197701

  However, even when using these methods, it is possible to obtain an undercoat layer that can satisfy all the characteristic values required for electrophotographic photoreceptors such as leakage resistance improvement, electrical property stabilization, and fogging even when using these methods. I couldn't.

  The present invention has been made in view of such problems, and has excellent electrical characteristics. Even when it is repeatedly used, the electrical characteristics do not fluctuate and image quality defects do not occur, and image quality defects such as pinhole leaks do not occur. An object is to provide an electrophotographic photosensitive member, and a process cartridge and an electrophotographic apparatus using the electrophotographic photosensitive member.

  As a result of intensive studies, the present inventors have obtained an electrophotographic photosensitive member having at least an undercoat layer and a photosensitive layer on a conductive substrate, and the undercoat layer can react with the metal oxide fine particles and the metal oxide fine particles. It has been found that the above-mentioned problems can be solved by containing an acceptor compound having a simple group.

  That is, by using the electrophotographic photoreceptor of the present invention provided with an undercoat layer containing metal oxide fine particles and an acceptor compound having a group capable of reacting with the metal oxide fine particles on a conductive substrate. Thus, stable electrical characteristics can be obtained even during long-term use, and good image quality with few image quality defects such as fogging, black spots, and ghosts can be obtained. Further, even if foreign matter generated from members around the electrophotographic photosensitive member or dust entering from the outside of the electrophotographic apparatus is pierced, the occurrence of leakage can be sufficiently prevented. Accordingly, it is possible to obtain sufficiently good image quality over a long period of time.

  Although the reason why the above-described effect can be obtained by the present invention is not necessarily clear, the present inventors infer as follows.

  Thicken the undercoat layer containing metal oxide particles to prevent the occurrence of leaks even if foreign matter generated from members around the electrophotographic photosensitive member or dust entering from the outside of the electrophotographic apparatus is pierced However, maintenance of sufficient electrical characteristics during long-term use has not been ensured. This is presumably because charges accumulated in the undercoat layer or near the interface between the undercoat layer and the upper layer during repeated use over a long period of time.

  When the acceptor compound having a group capable of reacting with the metal oxide particles is contained in the undercoat layer, the acceptor compound that reacts with and binds to the metal oxide fine particles in the undercoat layer is formed between the undercoat layer and the upper layer. It is considered that the increase in the residual potential during long-term use can be prevented by assisting charge transfer at the interface and preventing trapping of charges in the undercoat layer.

That is, the present invention is as follows.
<1> An electrophotographic photoreceptor having at least an undercoat layer and a photosensitive layer on a conductive substrate, wherein the undercoat layer has an anthraquinone structure having metal oxide fine particles and a group capable of reacting with the metal oxide fine particles. An electrophotographic photosensitive member containing a functional compound.

<2> The electrophotographic photosensitive member according to <1>, wherein the group capable of reacting with the metal oxide fine particles of the acceptor compound is a hydroxyl group.

< 3 > The electrophotographic photosensitive member according to <1> or <2> , wherein the acceptor compound is at least one selected from the group consisting of a hydroxyanthraquinone compound and an aminohydroxyanthraquinone compound. is there.
<4> The electrophotographic photosensitive member according to <3>, wherein the hydroxyanthraquinone compound is selected from alizarin, 1-hydroxyanthraquinone, and purpurin.

<5> The electrophotographic photosensitive member according to any one of <1> to <4>, wherein the metal oxide fine particles are surface-treated with a coupling agent.

<6> The electrophotographic photosensitive member according to any one of <1> to <5>, wherein the metal oxide fine particles are surface-treated with a silane coupling agent.

<7> The electrophotographic photosensitive member according to <6>, wherein the silane coupling agent is surface-treated with a silane coupling agent having an amino group.

<8> The method according to any one of <1> to <7>, wherein the metal oxide fine particles are at least one selected from the group consisting of titanium oxide, zinc oxide, tin oxide, and zirconium oxide. This is an electrophotographic photoreceptor.

<9> Any one of <1> to <8>, wherein the photosensitive layer has a charge generation layer, and the charge generation layer contains at least one of a phthalocyanine pigment or an azo pigment. The electrophotographic photoreceptor described in 1.

<10> The electrophotography according to <9>, wherein the phthalocyanine pigment is one selected from the group consisting of a hydroxygallium phthalocyanine pigment, a chlorogallium phthalocyanine pigment, an oxytitanyl phthalocyanine pigment, and a metal-free phthalocyanine pigment. It is a photoreceptor.

<11> The electrophotographic photosensitive member according to any one of <1> to <10>, wherein the outermost surface of the electrophotographic photosensitive member contains fluorine-based resin particles.

<12> The electrophotographic photosensitive member according to any one of <1> to <11>, and at least one of a charging device, a developing device, a cleaning device, and a static eliminator, and is attached to and detached from the main body of the electrophotographic device. It is a process cartridge characterized by being free at any time.

<13> An electrophotographic apparatus using the electrophotographic photosensitive member according to any one of <1> to <11>.

<14> The electrophotographic apparatus according to <13>, further comprising a contact-type charging device that contacts the photoreceptor and charges the photoreceptor.

<15> The electrophotographic apparatus according to <13>, further comprising an intermediate transfer device that transfers an image formed on the electrophotographic photosensitive member.

  According to the present invention, it is possible to obtain an electrophotographic photosensitive member that is excellent in electrical characteristics and obtains a good image quality. Even in the process cartridge and the electrophotographic apparatus using the electrophotographic photosensitive member, even when it is repeatedly used, there are few fluctuations in electrical characteristics and occurrence of image quality defects, and image quality defects such as pinhole leakage can be prevented. .

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings as the case may be. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and redundant description is omitted.

(Electrophotographic photoreceptor)
FIG. 1 is a schematic cross-sectional view showing an example of an electrophotographic photoreceptor according to the present invention. The electrophotographic photosensitive member 7 has a structure in which an undercoat layer 2, an intermediate layer 4, a photosensitive layer 3, and a protective layer 5 are sequentially laminated on a conductive substrate 1. The electrophotographic photoreceptor 7 shown in FIG. 2 is a function separation type photoreceptor, and the photosensitive layer 3 includes a charge generation layer 31 and a charge transport layer 32.

  As the conductive substrate 1, a metal drum such as aluminum, copper, iron, stainless steel, zinc, nickel, etc .; on a base material such as sheet, paper, plastic, glass, aluminum, copper, gold, silver, platinum, palladium, titanium, Deposited metal such as nickel-chromium, stainless steel, copper, indium, etc. or deposited conductive metal compound such as indium oxide and tin oxide; laminated metal foil on the above substrate or carbon black, indium oxide Tin oxide, antimony oxide powder, metal powder, copper iodide and the like are dispersed in a binder resin and subjected to a conductive treatment by applying it.

  The shape of the conductive substrate 1 is not limited to a drum shape, and may be a sheet shape or a plate shape. In addition, when the conductive substrate 1 is a metal pipe, the surface may be left as it is, or a process such as mirror cutting, etching, anodizing, rough cutting, centerless grinding, sand blasting, wet honing, etc. may be performed in advance. It may be done.

  The undercoat layer 2 is formed by containing metal oxide fine particles and an acceptor compound having a group capable of reacting with the metal oxide fine particles.

The metal oxide fine particles used in the present invention require a powder resistance of about 10 ² to 10 ¹¹ Ω · cm. The reason is that the undercoat layer needs to obtain an appropriate resistance in order to obtain leak resistance. Among these, metal oxide fine particles such as titanium oxide, zinc oxide, tin oxide and zirconium oxide having the above resistance values are preferably used. In particular, zinc oxide is preferably used. If the resistance value of the metal oxide fine particles is lower than the lower limit of the above range, sufficient leakage resistance cannot be obtained. If the resistance value is higher than the upper limit of the range, there is a concern that the residual potential is increased. Further, two or more kinds of metal oxide fine particles having different surface treatments or different particle diameters can be used in combination. As the metal oxide fine particles, those having a specific surface area of 10 m ² / g or more are preferably used. Those having a specific surface area value of 10 m ² / g or less are liable to cause a decrease in chargeability and have a drawback that it is difficult to obtain good electrophotographic characteristics.

  The metal oxide fine particles can be subjected to a surface treatment. The surface treatment agent can be selected from known materials as long as desired characteristics such as a silane coupling agent, a titanate coupling agent, an aluminum coupling agent, and a surfactant can be obtained. In particular, silane coupling agents are preferably used because they give good electrophotographic characteristics. Furthermore, a silane coupling agent having an amino group is preferably used because it gives a good blocking property to the undercoat layer.

  Any silane coupling agent having an amino group can be used as long as it can obtain desired photoreceptor characteristics. Specific examples include γ-aminopropyltriethoxysilane, N-β- (amino Ethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethylmethoxysilane, N, N-bis (β-hydroxyethyl) -γ-aminopropyltriethoxysilane, and the like. However, it is not limited to these. Moreover, 2 or more types of silane coupling agents can also be mixed and used. Examples of silane coupling agents that can be used in combination with the silane coupling agent having an amino group include vinyltrimethoxysilane, γ-methacryloxypropyl-tris (β-methoxyethoxy) silane, β- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β- (aminoethyl)- γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethylmethoxysilane, N, N-bis (β-hydroxyethyl) -γ-aminopropyltriethoxysilane, γ-chloropropyltri Examples include methoxysilane. The present invention is not limited to, et al.

  As the surface treatment method, any known method can be used, but a dry method or a wet method can be used.

  When surface treatment is performed by a dry method, a silane coupling agent dissolved directly or in an organic solvent is added dropwise and sprayed with dry air or nitrogen gas while stirring the metal oxide fine particles with a mixer having a large shearing force. Is uniformly processed. The addition or spraying is preferably performed at a temperature below the boiling point of the solvent. Spraying at a temperature equal to or higher than the boiling point of the solvent is not preferred because it causes the solvent to evaporate before being stirred uniformly, causing the silane coupling agent to locally accumulate and making uniform processing difficult. After addition or spraying, baking can be performed at 100 ° C. or higher. Baking can be carried out in an arbitrary range as long as the temperature and time allow the desired electrophotographic characteristics to be obtained.

  As a wet method, the metal oxide fine particles are stirred in a solvent, dispersed using ultrasonic waves, a sand mill, an attritor, a ball mill, etc., added with a silane coupling agent solution and stirred or dispersed, and then the solvent is removed. Uniformly processed. The solvent removal method is distilled off by filtration or distillation. After removing the solvent, baking can be performed at 100 ° C. or higher. Baking can be carried out in an arbitrary range as long as the temperature and time allow the desired electrophotographic characteristics to be obtained. In the wet method, the water containing metal oxide fine particles can be removed before adding the surface treatment agent. For example, a method of removing with stirring and heating in the solvent used for the surface treatment, removing by azeotroping with the solvent. It is also possible to use a method of

  The amount of the silane coupling agent relative to the metal oxide fine particles in the undercoat layer 2 can be arbitrarily set as long as desired electrophotographic characteristics can be obtained.

Any acceptor compound may be used as long as it has an anthraquinone structure having a group capable of reacting with metal oxide fine particles capable of obtaining desired characteristics, but a compound having a hydroxyl group is particularly preferably used. That is, an acceptor compound having an anthraquinone structure having a hydroxyl group is preferably used. Examples of the compound having an anthraquinone structure having a hydroxyl group include hydroxyanthraquinone compounds and aminohydroxyanthraquinone compounds, and any of them can be preferably used. More specifically, alizarin, quinizarin, anthralfin, purpurin, 1-hydroxyanthraquinone, 2-amino-3-hydroxyanthraquinone, 1-amino-4-hydroxyanthraquinone and the like are particularly preferably used.

  The content of the acceptor compound used in the present invention can be arbitrarily set as long as desired characteristics are obtained, but it is preferably used in the range of 0.01 to 20% by mass with respect to the metal oxide fine particles. More preferably, it is used in the range of 0.05 to 10% by mass with respect to the metal oxide. If it is 0.01% by mass or less, sufficient acceptor property that contributes to improvement of charge accumulation in the undercoat layer cannot be imparted, so that it tends to cause deterioration in sustainability such as increase in residual potential during repeated use. Further, when the content is 20% by mass or more, aggregation of metal oxides is likely to occur, so that when the undercoat layer is formed, the metal oxide cannot form a good conductive path in the undercoat layer. Not only is it likely to cause deterioration of maintainability such as an increase, but it also tends to cause image quality defects such as black spots.

  As the binder resin contained in the undercoat layer 2, any known resin can be used as long as it can form a good film and can obtain desired characteristics. For example, acetal such as polyvinyl butyral can be used. Resin, polyvinyl alcohol resin, casein, polyamide resin, cellulose resin, gelatin, polyurethane resin, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinyl acetate resin, vinyl chloride-vinyl acetate-maleic anhydride resin, silicone resin , Using known polymer resin compounds such as silicone-alkyd resin, phenol resin, phenol-formaldehyde resin, melamine resin, urethane resin, charge transport resin having a charge transport group, or conductive resin such as polyaniline, etc. Can do. Of these, resins insoluble in the upper coating solvent are preferably used, and phenol resins, phenol-formaldehyde resins, melamine resins, urethane resins, epoxy resins, and the like are particularly preferably used.

  The ratio between the metal oxide fine particles and the binder resin in the coating solution for forming the undercoat layer can be arbitrarily set within a range where desired electrophotographic photoreceptor characteristics can be obtained.

  Various additives can be used in the coating liquid for forming the undercoat layer in order to improve electrical characteristics, environmental stability, and image quality.

  As additives, quinone compounds such as chloranil and bromoanil, tetracyanoquinodimethane compounds, fluorenone compounds such as 2,4,7-trinitrofluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2- (4-biphenyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole, 2,5-bis (4-naphthyl) -1,3,4-oxadiazole, Oxadiazole compounds such as 2,5-bis (4-diethylaminophenyl) 1,3,4 oxadiazole, xanthone compounds, thiophene compounds, 3,3 ′, 5,5′tetra-t-butyldiphenoxy Electron transporting substances such as non-diphenoquinone compounds such as non-electron transporting pigments such as polycyclic condensation systems and azo systems, zirconium chelate compounds, titanium chelate compounds Aluminum chelate compounds, titanium alkoxide compounds, organic titanium compounds, there can be used a known material such as a silane coupling agent. The silane coupling agent is used for the surface treatment of the metal oxide, but it can also be added to the coating solution as an additive. Specific examples of the silane coupling agent used here include vinyltrimethoxysilane, γ-methacryloxypropyl-tris (β-methoxyethoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ- Glycidoxypropyltrimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (Aminoethyl) -γ-aminopropylmethylmethoxysilane, N, N-bis (β-hydroxyethyl) -γ-aminopropyltriethoxysilane, γ-chloropropyltrimethoxysilane, and the like. Examples of zirconium chelate compounds include zirconium butoxide, zirconium zirconium acetoacetate, zirconium triethanolamine, acetylacetonate zirconium butoxide, ethyl zirconium acetoacetate, zirconium acetate, zirconium oxalate, zirconium lactate, zirconium phosphonate, zirconium octoate, naphthene. Zirconate, zirconium laurate, zirconium stearate, zirconium isostearate, methacrylate zirconium butoxide, stearate zirconium butoxide, isostearate zirconium butoxide and the like.

  Examples of titanium chelate compounds include tetraisopropyl titanate, tetranormal butyl titanate, butyl titanate dimer, tetra (2-ethylhexyl) titanate, titanium acetylacetonate, polytitanium acetylacetonate, titanium octylene glycolate, titanium lactate ammonium salt, Examples thereof include titanium lactate, titanium lactate ethyl ester, titanium triethanolamate, and polyhydroxytitanium stearate.

  Examples of the aluminum chelate compound include aluminum isopropylate, monobutoxy aluminum diisopropylate, aluminum butyrate, diethyl acetoacetate aluminum diisopropylate, aluminum tris (ethyl acetoacetate) and the like.

  These compounds can be used alone or as a mixture or polycondensate of a plurality of compounds.

  As a solvent for adjusting the coating solution for forming the undercoat layer, any known organic solvent such as alcohol, aromatic, halogenated hydrocarbon, ketone, ketone alcohol, ether, ester, etc. You can choose. For example, methanol, ethanol, n-propanol, iso-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, ethyl acetate, n-butyl acetate, dioxane, tetrahydrofuran, Usual organic solvents such as methylene chloride, chloroform, chlorobenzene, and toluene can be used.

  Moreover, the solvent used for these dispersion | distribution can be used individually or in mixture of 2 or more types. When mixing, any solvent can be used as long as it can dissolve the binder resin as the mixed solvent.

  As a method of dispersing the metal oxide fine particles and the acceptor compound having a group capable of reacting with the metal oxide fine particles, known methods such as a roll mill, a ball mill, a vibrating ball mill, an attritor, a sand mill, a colloid mill, and a paint shaker are used. Can be used. Further, as the coating method used when the undercoat layer 2 is provided, conventional methods such as blade coating method, wire bar coating method, spray coating method, dip coating method, bead coating method, air knife coating method, curtain coating method, etc. Can be used.

  In the undercoat layer 2, the metal oxide fine particles and the acceptor compound having a group capable of reacting with the metal oxide fine particles may react during the dispersion step, or may react during the coating film drying / curing, It is preferable to react in a dispersion because it reacts uniformly.

  The undercoat layer 2 is formed on the conductive substrate using the undercoat layer forming coating solution thus obtained.

  The undercoat layer 2 preferably has a Vickers strength of 35 or more.

  Furthermore, the undercoat layer 2 can be set to any thickness as long as desired characteristics can be obtained, but the thickness is preferably 15 μm or more, more preferably 15 μm or more and 50 μm or less. preferable.

  When the thickness of the undercoat layer 2 is less than 15 μm, sufficient leak-proof performance cannot be obtained, and when it is 50 μm or more, a residual potential tends to remain during long-term use, so that it tends to cause abnormal image density. is there.

  Further, the surface roughness of the undercoat layer 2 is adjusted to ¼n (n is the refractive index of the upper layer) to ½λ of the exposure laser wavelength λ used in order to prevent moire images. In order to adjust the surface roughness, particles such as a resin can be added to the undercoat layer. As the resin particles, silicone resin particles, cross-linked PMMA resin particles, and the like can be used.

  In addition, the undercoat layer can be polished to adjust the surface roughness. As a polishing method, buffing, sand blasting, wet honing, grinding, or the like can be used.

  Further, an intermediate layer 4 may be provided between the undercoat layer 2 and the photosensitive layer 3 in order to improve electrical characteristics, improve image quality, improve image quality maintainability, and improve photosensitive layer adhesion.

  The intermediate layer 4 is acetal resin such as polyvinyl butyral, polyvinyl alcohol resin, casein, polyamide resin, cellulose resin, gelatin, polyurethane resin, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinyl acetate resin, vinyl chloride-acetic acid. In addition to polymer resin compounds such as vinyl-maleic anhydride resin, silicone resin, silicone-alkyd resin, phenol-formaldehyde resin, melamine resin, organometallic compounds containing zirconium, titanium, aluminum, manganese, silicon atoms, etc. There is. These compounds can be used alone or as a mixture or polycondensate of a plurality of compounds. Among them, an organometallic compound containing zirconium or silicon is excellent in performance such as a low residual potential, a small potential change due to the environment, and a small potential change due to repeated use.

  Examples of silicon compounds are vinyltrimethoxysilane, γ-methacryloxypropyl-tris (β-methoxyethoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane. , Vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ- Aminopropylmethylmethoxysilane, N, N-bis (β-hydroxyethyl) -γ-aminopropyltriethoxysilane, γ-chloropropyltrimethoxysilane, and the like. Among these, silicon compounds particularly preferably used are vinyltriethoxysilane, vinyltris (2-methoxyethoxysilane), 3-methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 2- (3,4). -Epoxycyclohexyl) ethyltrimethoxysilane, N-2- (aminoethyl) 3-aminopropyltrimethoxysilane, N-2- (aminoethyl) 3-aminopropylmethyldimethoxysilane, 3-aminopropyltriethoxysilane, N Silane coupling agents such as -phenyl-3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-chloropropyltrimethoxysilane are raised.

  Examples of organic zirconium compounds include zirconium butoxide, zirconium zirconium acetoacetate, zirconium triethanolamine, acetylacetonate zirconium butoxide, ethyl acetoacetate butoxide, zirconium acetate, zirconium oxalate, zirconium lactate, zirconium phosphonate, zirconium octoate, naphthene. Zirconate, zirconium laurate, zirconium stearate, zirconium isostearate, methacrylate zirconium butoxide, stearate zirconium butoxide, isostearate zirconium butoxide and the like.

  Examples of organic titanium compounds include tetraisopropyl titanate, tetranormal butyl titanate, butyl titanate dimer, tetra (2-ethylhexyl) titanate, titanium acetylacetonate, polytitanium acetylacetonate, titanium octylene glycolate, titanium lactate ammonium salt, Examples thereof include titanium lactate, titanium lactate ethyl ester, titanium triethanolamate, and polyhydroxytitanium stearate.

  Examples of the organoaluminum compound include aluminum isopropylate, monobutoxyaluminum diisopropylate, aluminum butyrate, diethyl acetoacetate aluminum diisopropylate, aluminum tris (ethyl acetoacetate) and the like.

  In addition to improving the coatability of the upper layer, the intermediate layer 4 also serves as an electrical blocking layer. However, if the film thickness is too large, the electrical barrier becomes too strong and the potential increases due to desensitization or repetition. cause. Therefore, when the intermediate layer 4 is formed, the film thickness is set to a range of 0.1 to 5 μm.

  The charge generation layer 31 constituting the photosensitive layer 3 is formed by forming a charge generation material by vacuum vapor deposition or by dispersing and applying it together with an organic solvent and a binder resin.

  When the charge generation layer 31 is formed by dispersion coating, the charge generation layer 31 is formed by dispersing the charge generation material together with an organic solvent, a binder resin, an additive, and the like and applying the obtained dispersion.

  In the present invention, any known charge generating material can be used as the charge generating material. For infrared light, phthalocyanine pigments, squarylium, bisazo, trisazo, perylene, dithioketopyrrolopyrrole, for visible light, condensed polycyclic pigments, bisazo, perylene, trigonal selenium, dye-sensitized zinc oxide fine particles, etc. are used. Among these, phthalocyanine pigments and azo pigments are used as charge generating materials that are particularly excellent and that are preferably used. By using this, it is possible to obtain the electrophotographic photosensitive member 7 with particularly high sensitivity and excellent repetitive stability. Further, phthalocyanine pigments and azo pigments generally have several crystal types, and any of these crystal types can be used as long as it is a crystal type capable of obtaining electrophotographic characteristics suitable for the purpose. Particularly preferred charge generating materials include chlorogallium phthalocyanine, dichlorotin phthalocyanine, hydroxygallium phthalocyanine, metal-free phthalocyanine, oxytitanyl phthalocyanine, chloroindium phthalocyanine, and the like.

  The phthalocyanine pigment crystal is obtained by mechanically dry-pulverizing a phthalocyanine pigment produced by a known method with an automatic mortar, planetary mill, vibration mill, CF mill, roller mill, sand mill, kneader, etc. It can manufacture by performing a wet grinding process using a ball mill, a mortar, a sand mill, a kneader, etc.

  Solvents used in the above treatment are aromatics (toluene, chlorobenzene, etc.), amides (dimethylformamide, N-methylpyrrolidone, etc.), aliphatic alcohols (methanol, ethanol, butanol, etc.), aliphatic polyvalents. Alcohols (ethylene glycol, glycerin, polyethylene glycol, etc.), aromatic alcohols (benzyl alcohol, phenethyl alcohol, etc.), esters (acetic ester, butyl acetate, etc.), ketones (acetone, methyl ethyl ketone, etc.), dimethyl sulfoxide, ether (Diethyl ether, tetrahydrofuran, etc.), several mixed systems, and mixed systems of water and these organic solvents. The solvent used is used in the range of 1 to 200 parts by weight, preferably 10 to 100 parts by weight, based on the pigment crystals. The treatment temperature is −20 ° C. to the boiling point of the solvent, preferably −10 to 60 ° C. In addition, grinding aids such as sodium chloride and sodium nitrate can be used during grinding. The grinding aid may be used 0.5 to 20 times, preferably 1 to 10 times the pigment.

  In addition, phthalocyanine pigment crystals produced by a known method can be controlled by combining acid pasting or acid pasting with dry pulverization or wet pulverization as described above. As an acid used for acid pasting, sulfuric acid is preferable, and a sulfuric acid having a concentration of 70 to 100%, preferably 95 to 100% is used, and a dissolution temperature is -20 to 100 ° C, preferably -10 to 60 ° C. Is set. The amount of concentrated sulfuric acid is set in the range of 1 to 100 times, preferably 3 to 50 times the mass of the phthalocyanine pigment crystals. As a solvent to be precipitated, water or a mixed solvent of water and an organic solvent is used in an arbitrary amount. The temperature for precipitation is not particularly limited, but it is preferably cooled with ice or the like in order to prevent heat generation.

  The binder resin used for the charge generation layer 31 can be selected from a wide range of insulating resins, and is selected from organic photoconductive polymers such as poly-N-vinylcarbazole, polyvinylanthracene, polyvinylpyrene, and polysilane. You can also. Preferred binder resins include polyvinyl acetal resin, polyarylate resin (polycondensate of bisphenol A and phthalic acid, etc.), polycarbonate resin, polyester resin, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyamide resin, acrylic resin Insulating resin such as polyacrylamide resin, polyvinyl pyridine resin, cellulose resin, urethane resin, epoxy resin, casein, polyvinyl alcohol resin, polyvinyl pyrrolidone resin can be used, but is not limited thereto. These binder resins can be used alone or in admixture of two or more. Of these, polyvinyl acetal resin is particularly preferably used.

  In the coating solution for forming the charge generation layer, the blending ratio (mass ratio) of the charge generation material and the binder resin is preferably in the range of 10: 1 to 1:10. The solvent for adjusting the coating solution can be arbitrarily selected from known organic solvents such as alcohols, aromatics, halogenated hydrocarbons, ketones, ketone alcohols, ethers, esters, and the like. . For example, methanol, ethanol, n-propanol, iso-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, ethyl acetate, n-butyl acetate, dioxane, tetrahydrofuran, Usual organic solvents such as methylene chloride, chloroform, chlorobenzene, and toluene can be used.

  Moreover, the solvent used for these dispersion | distribution can be used individually or in mixture of 2 or more types. When mixing, any solvent can be used as long as it can dissolve the binder resin as the mixed solvent.

  As a dispersion method, methods such as a roll mill, a ball mill, a vibration ball mill, an attritor, a sand mill, a colloid mill, and a paint shaker can be used. Further, as a coating method used when the charge generation layer 31 is provided, usual methods such as a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, and a curtain coating method are used. Can be used.

  Further, at the time of dispersion, it is effective for high sensitivity and high stability that the particles have a particle size of 0.5 μm or less, preferably 0.3 μm or less, more preferably 0.15 μm or less.

  Further, the charge generating material can be subjected to a surface treatment for improving the stability of electrical characteristics and preventing image quality defects. A coupling agent or the like can be used as the surface treatment agent, but the surface treatment agent is not limited to this. Examples of coupling agents used for the surface treatment include vinyltrimethoxysilane, γ-methacryloxypropyl-tris (β-methoxyethoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycol. Sidoxypropyltrimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- ( Examples of the silane coupling agent include aminoethyl) -γ-aminopropylmethylmethoxysilane, N, N-bis (β-hydroxyethyl) -γ-aminopropyltriethoxysilane, and γ-chloropropyltrimethoxysilane. Among these, silane coupling agents that are particularly preferably used are vinyltriethoxysilane, vinyltris (2-methoxyethoxysilane), 3-methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 2- ( 3,4-epoxycyclohexyl) ethyltrimethoxysilane, N-2- (aminoethyl) 3-aminopropyltrimethoxysilane, N-2- (aminoethyl) 3-aminopropylmethyldimethoxysilane, 3-aminopropyltriethoxy Examples of the silane coupling agent include silane, N-phenyl-3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-chloropropyltrimethoxysilane.

  Zirconium butoxide, zirconium zirconium acetoacetate, zirconium triethanolamine, acetylacetonate zirconium butoxide, ethyl acetoacetate butoxide, zirconium acetate, zirconium oxalate, zirconium lactate, zirconium phosphonate, zirconium octoate, zirconium naphthenate, lauric acid Organic zirconium compounds such as zirconium, zirconium stearate, zirconium isostearate, methacrylate zirconium butoxide, stearate zirconium butoxide, isostearate zirconium butoxide and the like can also be used.

  Tetraisopropyl titanate, tetranormal butyl titanate, butyl titanate dimer, tetra (2-ethylhexyl) titanate, titanium acetylacetonate, polytitanium acetylacetonate, titanium octylene glycolate, titanium lactate ammonium salt, titanium lactate, titanium lactate Organic titanium compounds such as ethyl ester, titanium triethanolamate, polyhydroxytitanium stearate, aluminum isopropylate, monobutoxy aluminum diisopropylate, aluminum butyrate, diethyl acetoacetate aluminum diisopropylate, aluminum tris (ethyl acetoacetate) An organoaluminum compound such as can also be used.

  Furthermore, various additives can be added to the coating solution for charge generation layer in order to improve electrical characteristics and image quality. Additives include quinone compounds such as chloranil, bromoanil, anthraquinone, tetracyanoquinodimethane compounds, fluorenones such as 2,4,7-trinitrofluorenone, 2,4,5,7-tetranitro-9-fluorenone Compounds, 2- (4-biphenyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole and 2,5-bis (4-naphthyl) -1,3,4-oxadi Azoles, oxadiazole compounds such as 2,5-bis (4-diethylaminophenyl) 1,3,4 oxadiazole, xanthone compounds, thiophene compounds, 3,3 ′, 5,5 ′ tetra-t-butyl Electron transporting substances such as diphenoquinone compounds such as diphenoquinone, electron transporting pigments such as polycyclic condensation systems and azo systems, zirconium chelate compounds, titani Known materials such as um chelate compounds, aluminum chelate compounds, titanium alkoxide compounds, organic titanium compounds, and silane coupling agents can be used.

  Examples of silane coupling agents include vinyltrimethoxysilane, γ-methacryloxypropyl-tris (β-methoxyethoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltri Methoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl)- γ-aminopropylmethylmethoxysilane, N, N-bis (β-hydroxyethyl) -γ-aminopropyltriethoxysilane, γ-chloropropyltrimethoxysilane, and the like.

  Examples of zirconium chelate compounds include zirconium butoxide, zirconium zirconium acetoacetate, zirconium triethanolamine, acetylacetonate zirconium butoxide, ethyl zirconium acetoacetate, zirconium acetate, zirconium oxalate, zirconium lactate, zirconium phosphonate, zirconium octoate, naphthene. Zirconate, zirconium laurate, zirconium stearate, zirconium isostearate, methacrylate zirconium butoxide, stearate zirconium butoxide, isostearate zirconium butoxide and the like.

  Examples of titanium chelate compounds include tetraisopropyl titanate, tetranormal butyl titanate, butyl titanate dimer, tetra (2-ethylhexyl) titanate, titanium acetylacetonate, polytitanium acetylacetonate, titanium octylene glycolate, titanium lactate ammonium salt, Examples thereof include titanium lactate, titanium lactate ethyl ester, titanium triethanolamate, and polyhydroxytitanium stearate.

  Examples of the aluminum chelate compound include aluminum isopropylate, monobutoxy aluminum diisopropylate, aluminum butyrate, diethyl acetoacetate aluminum diisopropylate, aluminum tris (ethyl acetoacetate) and the like.

  These compounds can be used alone or as a mixture or polycondensate of a plurality of compounds.

  Further, as a coating method used when the charge generation layer 31 is provided, usual methods such as a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, and a curtain coating method are used. Can be used.

  As the charge transport material contained in the charge transport layer 32, any known material can be used, but the following can be exemplified. Oxadiazole derivatives such as 2,5-bis (p-diethylaminophenyl) -1,3,4-oxadiazole, 1,3,5-triphenyl-pyrazoline, 1- [pyridyl- (2)]-3 Pyrazoline derivatives such as-(p-diethylaminostyryl) -5- (p-diethylaminostyryl) pyrazoline, triphenylamine, tri (P-methyl) phenylamine, N, N'-bis (3,4-dimethylphenyl) biphenyl Aromatic tertiary amino compounds such as -4-amine, dibenzylaniline, 9,9-dimethyl-N, N′-di (p-tolyl) fluoren-2-amine, N, N′-diphenyl-N, Aromatic tertiary diamino compounds such as N′-bis (3-methylphenyl)-[1,1-biphenyl] -4,4′-diamine, 3- (4′dimethylamino) 1,5,6-di- (4'-methoxyphenyl) -1,2,4-triazine, 1,2,4-triazine derivatives, 4-diethylaminobenzaldehyde-1,1-diphenylhydrazone, 4-diphenyl Hydrazone derivatives such as aminobenzaldehyde-1,1-diphenylhydrazone, [p- (diethylamino) phenyl] (1-naphthyl) phenylhydrazone, quinazoline derivatives such as 2-phenyl-4-styryl-quinazoline, 6-hydroxy-2, Benzofuran derivatives such as 3-di (p-methoxyphenyl) -benzofuran, α-stilbene derivatives such as p- (2,2-diphenylvinyl) -N, N′-diphenylaniline, enamine derivatives, N-ethylcarbazole, etc. Carbazole derivatives, poly-N-vinylcarbazole and its Hole transport materials such as derivatives. Quinone compounds such as chloranil, bromoanil, anthraquinone, tetracyanoquinodimethane compounds, fluorenone compounds such as 2,4,7-trinitrofluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2- ( 4-biphenyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole, 2,5-bis (4-naphthyl) -1,3,4-oxadiazole, 2,5 -Oxadiazole compounds such as bis (4-diethylaminophenyl) 1,3,4 oxadiazole, xanthone compounds, thiophene compounds, 3,3 ′, 5,5 ′ tetra-t-butyldiphenoquinone, etc. Electron transport materials such as diphenoquinone compounds. Or the polymer etc. which have the group which consists of a compound shown above in the principal chain or a side chain are mention | raise | lifted. These charge transport materials can be used alone or in combination of two or more.

  Among these, the following structural formulas (A) to (C) are preferable from the viewpoint of mobility.

(In the formula (A), R ¹⁴ represents a methyl group. N ′ represents an integer of 0 to 2. Ar ⁶ and Ar ⁷ represent a substituted or unsubstituted aryl group, or —C (R ¹⁸ ) = C (R ¹⁹ ) (R ²⁰ ), —CH═CH—CH═C (Ar) ₂ , and the substituent is a halogen atom, an alkyl group having 1 to 5 carbon atoms, or 1 carbon atom. Represents a substituted amino group substituted with an alkoxy group in the range of ˜5 or an alkyl group having a carbon number of 1 to 3. Ar represents a substituted or unsubstituted aryl group, R ¹⁸ , R ¹⁹ , R ²⁰ Represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group.

(In formula (B), R ¹⁵ and R ¹⁵ ′ may be the same or different and each represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms. R ¹⁶ , R ¹⁶ ′, R ¹⁷ and R ¹⁷ ′ may be the same or different and are a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or an alkyl group having 1 to 2 carbon atoms. Represents an amino group substituted with or a substituted or unsubstituted aryl group, or —C (R ¹⁸ ) ═C (R ¹⁹ ) (R ²⁰ ), —CH═CH—CH═C (Ar ′) ₂ . Ar ′ represents a substituted or unsubstituted aryl group, and R ¹⁸ , R ¹⁹ and R ²⁰ represent a hydrogen atom, a substituted or unsubstituted alkyl group, and a substituted or unsubstituted aryl group. '' Is an integer from 0 to 2.)

(In the formula (C), R ²¹ represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a substituted or unsubstituted aryl group, or —CH═CH—CH═C (Ar '') .Ar representing the ₂ '', the .R ^22, R ²³ to represent a substituted or unsubstituted aryl group may be the same or different, a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, This represents an alkoxy group having 1 to 5 carbon atoms, an amino group substituted with an alkyl group having 1 to 2 carbon atoms, or a substituted or unsubstituted aryl group.

  Any binder resin may be used as long as it is a known binder resin for the charge transport layer 32, but an electrically insulating resin capable of forming a film is preferable. For example, polycarbonate resin, polyester resin, polyarylate resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin, polystyrene resin, acrylonitrile-styrene copolymer, acrylonitrile-butadiene copolymer, polyvinyl acetate resin, styrene -Butadiene copolymer, vinylidene chloride-acrylonitrile copolymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, silicone resin, silicone-alkyd resin, phenol-formaldehyde resin, styrene N-alkyd resin, poly N-carbazole, polyvinyl butyral, polyvinyl formal, polysulfone, casein, gelatin, polyvinyl alcohol, ethyl cellulose, pheno Resin, polyamide, polyacrylamide, carboxymethylcellulose, vinylidene chloride polymer wax, insulating resin such as polyurethane, and polyvinylcarbazole, polyvinylanthracene, polyvinylpyrene, polysilane, JP-A-8-176293 and JP-A-8-208820 Polymer charge transport materials such as polyester-based polymer charge transport materials disclosed in Japanese Patent Publication No. Gazette can also be used. These binder resins can be used alone or in admixture of two or more. These binder resins are used singly or in combination of two or more. In particular, polycarbonate resins, polyester resins, methacrylic resins, and acrylic resins are compatible with charge transport materials, soluble in solvents, and strong. Excellent and preferably used. The mixing ratio (mass ratio) between the binder resin and the charge transport material can be arbitrarily set in any case, but attention must be paid to a decrease in electrical characteristics and a decrease in film strength.

  A polymer charge transport material can also be used alone. As the polymer charge transporting material, known materials having charge transporting properties such as poly-N-vinylcarbazole and polysilane can be used. In particular, polyester polymer charge transport materials disclosed in JP-A-8-176293 and JP-A-8-208820 have a high charge transporting property and are particularly preferable. The polymer charge transport material alone can be used as the charge transport layer, but it may be formed by mixing with the binder resin.

  Further, when the charge transport layer 32 is a surface layer of the electrophotographic photosensitive member 7 (a layer disposed on the side farthest from the conductive substrate 1 of the photosensitive layer), the charge transport layer 32 imparts lubricity to the surface. In order to make the layer difficult to wear or scratch, and to improve the cleaning property of the developer adhered to the surface of the photoreceptor, lubricating particles (for example, silica particles, alumina particles, polytetrafluoroethylene (PTFE) ) -Based fluororesin particles and silicone-based resin particles). These lubricating particles can be used in combination of two or more. In particular, fluorine resin particles are preferably used.

  Fluorine-based resin particles include tetrafluoroethylene resin, trifluorinated ethylene resin, hexafluoropropylene resin, vinyl fluoride resin, vinylidene fluoride resin, difluorodiethylene chloride resin and copolymers thereof. It is desirable to appropriately select one or two or more kinds from among them, and particularly preferred are tetrafluoroethylene resin and vinylidene fluoride resin.

  The average particle diameter of the primary particles of the fluororesin is preferably 0.05 to 1 μm, more preferably 0.1 to 0.5 μm. When the average particle diameter of the primary particles is less than 0.05 μm, aggregation during dispersion or after dispersion tends to proceed. If it exceeds 1 μm, image quality defects are likely to occur.

  The content of the fluoric resin in the charge transport layer 32 in the charge transport layer 32 containing the fluoric resin is suitably 0.1 to 40% by weight, particularly 1 to 30% by weight, based on the total amount of the charge transport layer 32. % Is preferred. If the content is less than 0.1% by mass, the modification effect due to the dispersion of the fluororesin particles is not sufficient. On the other hand, if it exceeds 40% by mass, the light transmission property is lowered and the residual potential is increased by repeated use. Will arise.

  The charge transport layer 32 can be formed by applying and drying a charge transport layer forming coating solution in which a charge transport material, a binder resin, and other materials are dissolved in a suitable solvent.

  Examples of the solvent used for forming the charge transport layer 32 include aromatic hydrocarbon solvents such as toluene and chlorobenzene, aliphatic alcohol solvents such as methanol, ethanol, and n-butanol, acetone, cyclohexanone, and 2-butanone. Such as ketone solvents, halogenated aliphatic hydrocarbon solvents such as methylene chloride, chloroform and ethylene chloride, cyclic or linear ether solvents such as tetrahydrofuran, dioxane, ethylene glycol and diethyl ether, or mixed solvents thereof Can be used. The mixing ratio of the charge transport material and the binder resin is preferably 10: 1 to 1: 5.

  Further, a slight amount of a leveling agent such as silicone oil for improving the smoothness of the coating film can be added to the coating solution for forming the charge transport layer.

  As a method for dispersing the fluorine-based resin in the charge transport layer 32, a roll mill, a ball mill, a vibrating ball mill, an attritor, a sand mill, a high-pressure homogenizer, an ultrasonic disperser, a colloid mill, a collision-type medialess disperser, a through-type medialess A method such as a disperser can be used.

  Examples of the dispersion of the coating liquid for forming the charge transport layer 32 include a method in which fluorine-based resin particles are dispersed in a solution such as a binder resin or a charge transport material dissolved in a solvent.

  In the step of producing a coating liquid for forming the charge transport layer 32, the temperature of the coating liquid is preferably controlled in the range of 0 ° C to 50 ° C.

  As a method of controlling the temperature of the coating liquid in the coating liquid manufacturing process to 0 ° C. to 50 ° C., cool with water, cool with wind, cool with refrigerant, adjust the room temperature of the manufacturing process, warm with hot water, with hot air You can use methods such as warming, heating with a heater, creating a coating liquid manufacturing facility with a material that does not easily generate heat, creating a coating liquid manufacturing facility with a material that easily dissipates heat, or creating a coating liquid manufacturing facility with a material that easily stores heat. .

  It is also effective to add a small amount of a dispersion aid in order to improve the dispersion stability of the dispersion and to prevent aggregation during the formation of the coating film. Examples of the dispersion aid include fluorine-based surfactants, fluorine-based polymers, silicone-based polymers, and silicone oils. Further, after dispersing, stirring, and mixing the fluororesin and the dispersion aid in a small amount of a dispersion solvent in advance, the mixture is dissolved and mixed with a solution obtained by mixing and dissolving the charge transport material, the binder resin, and the dispersion solvent, and then the method is performed. It is also an effective means to disperse.

  The coating methods used when providing the charge transport layer 32 include dip coating, push-up coating, spray coating, roll coater coating, wire bar coating, gravure coater coating, bead coating, curtain coating, A blade coating method, an air knife coating method, or the like can be used.

  The thickness of the charge transport layer 32 is preferably 5 to 50 μm, and more preferably 10 to 45 μm.

  Further, the electrophotographic photosensitive member 7 of the present invention has an anti-oxidation function in the photosensitive layer 3 for the purpose of preventing the deterioration of the electrophotographic photosensitive member 7 due to ozone, oxidizing gas, or light / heat generated in the electrophotographic apparatus. Additives such as oxidants and light stabilizers can be added.

  Examples of the antioxidant include hindered phenol, hindered amine, paraphenylenediamine, arylalkane, hydroquinone, spirochroman, spiroidanone and their derivatives, organic sulfur compounds, and organic phosphorus compounds.

  Specific examples of antioxidants include phenolic antioxidants such as 2,6-di-tert-butyl-4-methylphenol, styrenated phenol, n-octadecyl-3- (3 ′, 5′-di). -T-butyl 4'-hydroxyphenyl) -propionate, 2,2'-methylene-bis- (4-methyl-6-t-butylphenol), 2-t-butyl-6- (3'-t-butyl) -5'-methyl-2'-hydroxybenzyl) -4-methylphenyl acrylate, 4,4'-butylidene-bis- (3-methyl-6-tert-butyl-phenol), 4,4'-thio-bis -(3-methyl 6-tert-butylphenol), 1,3,5-tris (4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanurate, tetrakis- [methyle -3- (3 ', 5'-di-t-butyl-4'-hydroxy-phenyl) propionate] -methane, 3,9-bis [2- [3- (3-t-butyl-4-hydroxy- 5-methylphenyl) propionyloxy] -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5,5] undecane.

  Among hindered amine compounds, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, 1- [2- [3 -(3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy] ethyl] -4- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy] -2, 2,6,6-tetramethylpiperidine, 8-benzyl-7,7,9,9-tetramethyl-3-octyl-1,3,8-triazaspiro [4,5] undecane-2,4-dione, 4, -Benzoyloxy-2,2,6,6-tetramethylpiperidine, dimethyl-1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine heavy succinate Compound, poly [{6- (1,1,3,3-tetramethylbutyl) imino-1,3,5-triazine-2,4-diimyl} {(2,2,6,6-tetramethyl- 4-piperidyl) imino} hexamethylene {(2,3,6,6, -tetramethyl-4-piperidyl) imino}], 2- (3,5-di-t-butyl-4-hydroxybenzyl) -2 N-Butylmalonate bis (1,2,2,6,6-pentamethyl-4-piperidyl), N, N′-bis (3-aminopropyl) ethylenediamine-2,4-bis [N-butyl-N -(1,2,2,6,6-pentamethyl-4piperidyl) amino] -6-chloro-1,3,5-triazine condensate and the like.

  Dilauryl-3,3′-thiodipropionate, dimyristyl-3,3′-thiodipropionate, distearyl-3,3′-thiodipropionate, pentaerythritol-tetrakis- ( β-lauryl-thiopropionate), ditridecyl-3,3′-thiodipropionate, 2-mercaptobenzimidazole and the like.

  Examples of the organophosphorus antioxidant include trisnonylphenyl phosfte, triphenyl phosfeft, tris (2,4-di-t-butylphenyl) -phosfte and the like.

  Organic sulfur-based and organic phosphorus-based antioxidants are referred to as secondary antioxidants, and a synergistic effect can be obtained by using them together with primary antioxidants such as phenols or amines.

  Examples of the light stabilizer include benzophenone, benzotriazole, dithiocarbamate, and tetramethylpiperidine derivatives.

  Examples of the benzophenone light stabilizer include 2-hydroxy-4-methoxy benzophenone, 2-hydroxy-4-octoxy benzophenone, and 2,2'-di-hydroxy-4-methoxy benzophenone. As a benzotriazole-based light stabilizer, 2- (2′-hydroxy-5′methylphenyl-)-benzotriazole, 2- [2′-hydroxy-3 ′-(3 ″, 4 ″, 5 ″, 6 ″ -tetra-hydrophthalimido-methyl) -5′-methylphenyl] -benzotriazole, 2- (2′-hydroxy-3′-tert-butyl5′-methylphenyl-)-5-chlorobenzotriazole, 2- (2′-hydroxy-3′-t-butyl 5′-methylphenyl-)-5-chlorobenzotriazole, 2- (2′-hydroxy-3 ′, 5′-t-butylphenyl-)-benzo Triazole, 2- (2′-hydroxy-5′-t-octylphenyl) -benzotriazole, 2- (2′-hydroxy 3 ′, 5′-di-t-amylphenyl-) Benzotriazole.

  Other compounds include 2,4-di-t-butylphenyl 3 ', 5'-di-t-butyl-4'-hydroxybenzoate, nickel dibutyl-dithiocarbamate and the like.

  Further, at least one kind of electron accepting substance can be included for the purpose of improving sensitivity, reducing residual potential, reducing fatigue during repeated use, and the like.

Examples of electron accepting substances include succinic anhydride, maleic anhydride, dibromomaleic anhydride, phthalic anhydride, tetrabromophthalic anhydride, tetracyanoethylene, tetracyanoquinodimethane, o-dinitrobenzene, m-dinitrobenzene, Examples include chloranil, dinitroanthraquinone, trinitrofluorenone, picric acid, o-nitrobenzoic acid, p-nitrobenzoic acid, and phthalic acid. Of these, fluorenone-based, quinone-based, and benzene derivatives having electron-withdrawing substituents such as Cl, CN, NO ₂ are particularly preferable.

  In the electrophotographic photosensitive member 7 having a laminated structure, the protective layer 5 prevents chemical change of the charge transport layer during charging, improves the mechanical strength of the photosensitive layer, and is resistant to abrasion and scratches on the surface layer. Used to further improve

  Examples of the form of the protective layer 5 include a cured resin film including a curable resin and a charge transporting compound, and a film formed by including a conductive material in an appropriate binder resin. Are more preferably used.

  Any known resin can be used as the curable resin, but those having a crosslinked structure are preferred from the viewpoint of strength, electrical characteristics, image quality maintenance, etc., for example, phenol resin, urethane resin, melamine resin, diallyl Examples include phthalate resins and siloxane resins.

  Of these, the protective layer 5 containing a siloxane-based resin having a structural unit having charge transporting capability and having a crosslinked structure is more preferable.

  As the protective layer 5, the cured film formed including the compound represented by the following general formula (I-1) or (I-2) is preferable.

F- [D-Si (R ² ) _(3-a) Q _a ] _b General formula (I-1)

In general formula (I-1), F represents an organic group derived from a photofunctional compound. D represents a flexible subunit. R ² represents hydrogen, an alkyl group, or a substituted or unsubstituted aryl group. Q represents a hydrolyzable group. a represents an integer of 1 to 3. b represents an integer of 1 to 4;

^{F - ((X) nR 1} -ZH) m Formula (I-2)

In general formula (I-2), F is an organic group derived from a compound having a hole transporting ability, R ¹ is an alkylene group, Z is an oxygen atom, a sulfur atom or NH, CO ₂ , COOH, and m is 1-4. Indicates an integer. X represents oxygen or sulfur, and n represents 0 or 1.

  In general formulas (I-1) and (I-2), F is a unit having photoelectric characteristics, specifically, photocarrier transport characteristics, and a structure conventionally known as a charge transport material is used as it is. be able to. Specifically, a compound skeleton having hole transport properties such as a triarylamine compound, a benzidine compound, an arylalkane compound, an aryl-substituted ethylene compound, a stilbene compound, an anthracene compound, a hydrazone compound, and the like, and A compound skeleton having electron transport properties such as a quinone compound, a fluorenone compound, a xanthone compound, a benzophenone compound, a cyanovinyl compound, and an ethylene compound can be used.

In the general formula (I-1), a substituted silicon group having a hydrolyzable group represented by —Si (R ² ) _(3-a) Q _a is represented, and the substituted silicon is crosslinked to each other by the Si group. A reaction is caused to form a three-dimensional Si—O—Si bond. That is, this substituted silicon group plays a role of forming a so-called inorganic glassy network in the protective layer 5.

In general formula (I-1), D represents a flexible subunit. Specifically, D is directly connected to an F site for imparting photoelectric characteristics and a three-dimensional inorganic glassy network. It represents an organic group that plays a role of linking to a substituted silicon group and imparts an appropriate flexibility to an inorganic vitreous network that is hard but brittle and improves the toughness of the film. Specific examples _{D, -C n H 2n -,} - C n H (2n-2) -, - C n H (2n-4) - 2 divalent hydrocarbon group (here represented, n is Represents an integer of 1 to 15.), —COO—, —S—, —O—, —CH ₂ —C ₆ H ₄ —, —N═CH—, — (C ₆ H ₄ ) — (C ₆ H). ₄ )-and the characteristic group which combined these arbitrarily, Furthermore, what substituted the structural atom of these characteristic groups with the other substituent, etc. are mentioned.

  In general formula (I-1), b is preferably 2 or more. When b is 2 or more, the photofunctional organosilicon compound represented by the general formula (I-1) contains two or more Si atoms, and an inorganic glassy network is easily formed. Strength is improved.

  As the compounds represented by the general formulas (I-1) and (I-2), a compound in which the organic group F is particularly represented by the following general formula (I-3) is preferable. The compound represented by the following general formula (I-3) is a compound having a hole transporting ability (hole transporting material), and the inclusion of this in the protective layer 5 is particularly suitable for the photoelectric characteristics and mechanical properties in the protective layer 5. It is preferable from the viewpoint of improving the characteristics.

(In general formula (I-3), Ar ^{1 to} Ar ⁴ each independently represents a substituted or unsubstituted aryl group. Ar ⁵ represents a substituted or unsubstituted aryl group or an arylene group, provided that 2 to 4 of Ar ^{1 to} Ar ⁵ have a bond represented by —D—Si (R ² ) _(3-a) Q _a, D represents a flexible subunit, and R ² represents hydrogen. Represents an alkyl group, a substituted or unsubstituted aryl group, Q represents a hydrolyzable group, and a represents an integer of 1 to 3.)

In the general formula (I-3), specifically, Ar ^{1 to} Ar ⁵ are preferably those represented by the following formulas (I-4) to (I-10).

Here, in formulas (I-4) to (I-10), each R ⁵ is independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkyl group having 1 to 4 carbon atoms, or 1 to 1 carbon atoms. 4 represents one type selected from the group consisting of a phenyl group substituted with 4 alkoxy groups, an unsubstituted phenyl group, and an aralkyl group having 7 to 10 carbon atoms. R ⁶ represents one selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, and a halogen atom. Further, X represents a characteristic group having a structure represented by the aforementioned _{^{-D-Si (R 2) (}} 3-a) Q a, m and s each represents 0 or 1, t is 1 to 3 Represents an integer.

  In the formula (I-10), Ar is preferably represented by the following formulas (I-11) to (I-12).

In formulas (I-11) and (I-12), R ⁶ has the same meaning as R ⁶ described above. T represents an integer of 1 to 3.

  In formula (I-10), Z ′ is preferably represented by the following formulas (I-13) to (I-14).

Further, as described above, wherein (I-4) ~ (I -10), X has a structure represented by the aforementioned _{^{-D-Si (R 2) (}} 3-a) Q a characteristic Represents a group. Y ¹ in the characteristic group is a divalent hydrocarbon group represented by —C ₁ H _2l —, —C _m H _2m-2 —, or —C _n H _2n-4 — (wherein , L represents an integer of 1 to 15, m represents an integer of 2 to 15, and n represents an integer of 3 to 15), -N = CH-, -O-, -COO-,- S-,-(CH) β- (β represents an integer of 1 to 10), the general formula (I-11) described above, the general formula (I-12) described above, and the following general formula (I -13) and the characteristic group represented by (I-14).

ここで、式（Ｉ−１４）中、ｙ及びｚはそれぞれ１〜５の整数を表し、ｔは１〜３の整数を表し、先に述べたようにＲ⁶は水素原子、炭素数１〜４のアルキル基、炭素数１〜４のアルコキシ基、ハロゲン原子からなる群より選ばれる１種を表す。

Here, in formula (I-14), y and z each represent an integer of 1 to 5, t represents an integer of 1 to 3, and as described above, R ⁶ represents a hydrogen atom, a carbon number of 1 to 1 type chosen from the group which consists of a 4 alkyl group, a C1-C4 alkoxy group, and a halogen atom.

In general formula (I-3), Ar ⁵ represents a substituted or unsubstituted aryl group or arylene group, and when k = 0, any one of formulas (I-15) to (I-19) shown in Table 4 Those that apply to the formula (I-20) to (I-24) shown in Table 5 are more preferable when k = 1.

In formulas (I-15) to (I-24), each R ⁵ independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkyl group having 1 to 4 carbon atoms, or an alkoxy having 1 to 4 carbon atoms. 1 type chosen from the group which consists of a phenyl group substituted by group, an unsubstituted phenyl group, and a C7-C10 aralkyl group. R ⁶ represents one selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, and a halogen atom. s represents 0 or 1, and t represents an integer of 1 to 3.

Ar ⁵ in formula (I-3) is any one of formulas (I-15) to (I-19) shown in Table 4, and further formulas (I-20) to (I) shown in Table 5. In the case of taking any structure of -24), Z in the formulas (I-19) and (I-24) is selected from the group consisting of the following general formulas (I-25) to (I-32) It is preferable that it is 1 type.

ここで、式（Ｉ−２５）〜（Ｉ−３２）中、Ｒ⁷はそれぞれ水素原子、炭素数１〜４のアルキル基、炭素数１〜４のアルコキシ基及びハロゲン原子からなる群より選ばれる１種を表し、Ｗは２価の基を表し、ｑ及びｒはそれぞれ１〜１０の整数を表し、ｔ’は１〜２の整数、をそれぞれ表す。

Here, in formulas (I-25) to (I-32), R ⁷ is selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, and a halogen atom. 1 type is represented, W represents a bivalent group, q and r represent the integer of 1-10, respectively, and t 'represents the integer of 1-2, respectively.

  W in the formulas (I-31) and (I-32) is preferably any one of divalent groups represented by the following (I-33) to (I-41). In formula (I-40), s ′ represents an integer of 0 to 3.

—CH ₂ — (I-33)
-C (CH ₃ ) _2- (I-34)
-O- (I-35)
-S- (I-36)
-C (CF ₃ ) _2- (I-37)
—Si (CH ₃ ) ₂ — (I-38)

Moreover, as a specific example of a compound represented by general formula (I-3), the thing of the compound numbers 1-274 of Table 1-Table 55 in Unexamined-Japanese-Patent No. 2001-83728 can be used, for example.

The charge transporting compound represented by the general formula (I-1) may be used alone or in combination of two or more.

  A compound represented by the following general formula (II) may be used in combination with the charge transporting compound represented by the general formula (I-1) for the purpose of further improving the mechanical strength of the cured film.

B- (Si (R ² ) _(3-a) Q _a ) ₂ General formula (II)

(In the general formula (II), B represents a divalent organic group, R ² represents hydrogen, an alkyl group, a substituted or unsubstituted aryl group, Q represents a hydrolyzable group, and a represents an integer of 1 to 3. .)

  Examples of the compound represented by the general formula (II) include those represented by the following formulas (II-1) to (II-5). The present invention is not limited by these.

In formulas (II-1) to (II-5), T ¹ and T ² each independently represent a divalent or trivalent hydrocarbon group. A represents the substituted silicon group having hydrolyzability described above. h, i, and j each independently represent an integer of 1 to 3. The compounds represented by formulas (II-1) to (II-5) are selected so that the number of A in the molecule is 2 or more.

  Specific preferred examples of the compound represented by the general formula (II) are shown in Tables 9 and 10 below as formulas (III-1) to (III-19). In Tables 9 and 10, Me represents a methyl group, Et represents an ethyl group, and Pr represents a propyl group.

  In addition to the compound represented by the general formula (I), another compound capable of crosslinking reaction may be used in combination. As such a compound, various silane coupling agents and commercially available silicon-based hard coat agents can be used.

  As silane coupling agents, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxy Silane, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropylmethyldimethoxysilane, N-β (aminoethyl) γ-aminopropyltriethoxysilane, tetramethoxysilane, methyltrimethoxysilane, Examples include dimethyldimethoxysilane.

  As a commercially available hard coat agent, KP-85, CR-39, X-12-2208, X-40-9740, X-41-1007, KNS-5300, X-40-2239 (above, manufactured by Shin-Etsu Silicone Co., Ltd.) ), AY42-440, AY42-441, AY49-208 (manufactured by Toray Dow Corning Co., Ltd.), and the like.

  Further, a fluorine atom-containing compound can be added to the protective layer 5 for the purpose of imparting surface lubricity. By improving the surface lubricity, the coefficient of friction with the cleaning member decreases, and the wear resistance can be improved. Further, it also has an effect of preventing adhesion of discharge products, developer, paper dust, and the like to the surface of the electrophotographic photosensitive member, which is useful for improving the life of the electrophotographic photosensitive member 7.

  As a specific example of the fluorine-containing compound, a fluorine atom-containing polymer such as polytetrafluoroethylene can be added as it is, or fine particles of these polymers can be added.

  Further, in the case where the protective layer 5 is a cured film formed of the compound represented by the general formula (I), a fluorine-containing compound that can react with alkoxysilane is added to constitute a part of the crosslinked film. Is desirable.

  Specific examples of such a fluorine atom-containing compound include (tridecafluoro-1,1,2,2-tetrahydrooctyl) triethoxysilane, (3,3,3-trifluoropropyl) trimethoxysilane, 3- ( Heptafluoroisopropoxy) propyltriethoxysilane, 1H, 1H, 2H, 2H-perfluoroalkyltriethoxysilane, 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane, 1H, 1H, 2H, 2H-perfluoro And octyltriethoxysilane.

  The addition amount of the fluorine-containing compound is preferably 20% by mass or less. Beyond this, a problem may occur in the film formability of the crosslinked cured film.

  The protective layer 5 has sufficient oxidation resistance, but an antioxidant may be added for the purpose of imparting stronger oxidation resistance.

  Antioxidants are preferably hindered phenols or hindered amines, organic sulfur antioxidants, phosphite antioxidants, dithiocarbamate antioxidants, thiourea antioxidants, benzimidazole antioxidants. , Etc., may be used. The addition amount of the antioxidant is preferably 15% by mass or less, and more preferably 10% by mass or less.

  Examples of the hindered phenol antioxidant include 2,6-di-t-butyl-4-methylphenol, 2,5-di-t-butylhydroquinone, N, N′-hexamethylene bis (3,5-di). -T-butyl-4-hydroxyhydrocinnamide, 3,5-di-t-butyl-4-hydroxy-benzylphosphonate-diethyl ester, 2,4-bis [(octylthio) methyl] -o-cresol, 2,6-di-t-butyl-4-ethylphenol, 2,2'-methylenebis (4-methyl-6-t-butylphenol), 2,2'-methylenebis (4-ethyl-6-t-butylphenol) 4,4'-butylidenebis (3-methyl-6-t-butylphenol), 2,5-di-t-amylhydroquinone, 2-t-butyl-6- (3-butyl-2- Dorokishi 5 methylbenzyl) -4-4,4'-butylidene bis (3-methyl -6-t-butylphenol), and the like.

  It is possible to add other additives used for forming a known coating film to the protective layer 5, and use known materials such as a leveling agent, an ultraviolet absorber, a light stabilizer, and a surfactant. Can do.

  In order to form the protective layer 5, a mixture of the above-described various materials and various additives is applied onto the photosensitive layer and heat-treated. Thereby, a cross-linking curing reaction is caused three-dimensionally to form a strong cured film. The temperature of the heat treatment is not particularly limited as long as it does not affect the underlying photosensitive layer, but is preferably set to room temperature to 200 ° C, particularly 100 to 160 ° C.

  In the formation of the protective layer 5, the crosslinking curing reaction may be performed without a catalyst, but an appropriate catalyst may be used. Catalysts include acid catalysts such as hydrochloric acid, sulfuric acid, phosphoric acid, formic acid, acetic acid, trifluoroacetic acid, bases such as ammonia and triethylamine, organic tin compounds such as dibutyltin diacetate, dibutyltin dioctoate, stannous oxalate, Examples thereof include organic titanium compounds such as tetra-n-butyl titanate and tetraisopropyl titanate, iron salts of organic carboxylic acids, manganese salts, cobalt salts, zinc salts, zirconium salts, and aluminum chelate compounds.

  The protective layer 5 can be used by adding a solvent as required for easy application. Specifically, water, methanol, ethanol, n-propanol, i-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, n-butyl acetate, dioxane, tetrahydrofuran, Examples of the organic solvent include methylene chloride, chloroform, dimethyl ether, and dibutyl ether. These can be used individually by 1 type or in mixture of 2 or more types.

  In the formation of the protective layer, as a coating method, a normal method such as a blade coating method, a Meyer bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, or a curtain coating method may be used. it can.

  The protective layer preferably has a thickness of 0.5 to 20 μm, particularly 2 to 10 μm.

  In the electrophotographic photosensitive member 7, the thickness of the functional layer above the charge generation layer 31 for obtaining high resolution is preferably 50 μm or less, preferably 40 μm or less. When the functional layer is a thin film, the combination of the particle-dispersed undercoat layer of the present invention and a high-strength protective layer is particularly effectively used.

  The electrophotographic photoreceptor 7 is not limited to the above configuration. For example, the electrophotographic photoreceptor 7 may have a configuration in which the intermediate layer 4 and / or the protective layer 5 are not present. That is, a configuration in which the undercoat layer 2 and the photosensitive layer 3 are formed on the conductive substrate 1, and a configuration in which the undercoat layer 2, the intermediate layer 4 and the photosensitive layer 3 are sequentially formed on the conductive substrate 1. Alternatively, a structure in which the undercoat layer 2, the photosensitive layer 3, and the protective layer 5 are sequentially formed on the conductive substrate 1 may be used.

  In addition, the stacking order of the charge generation layer 31 and the charge transport layer 32 may be reversed. Further, the photosensitive layer 3 may have a single layer structure. In that case, a protective layer may be provided on the photosensitive layer, or both an undercoat layer and a protective layer may be provided. Further, the intermediate layer 4 may be provided on the undercoat layer as described above.

(Electrophotographic equipment)
FIG. 2 is a schematic view showing a preferred embodiment of the electrophotographic apparatus of the present invention.
An electrophotographic apparatus 100 shown in FIG. 2 includes a drum-shaped (cylindrical) electrophotographic photosensitive member 7 of the present invention that is rotatably provided. Around the electrophotographic photosensitive member 7, a charging device 8, an exposure device 10, a developing device 11, a transfer device 12, a cleaning device 13, and a static eliminator (erase) are arranged along the movement direction of the outer peripheral surface of the electrophotographic photosensitive member 7. Device) 14 are arranged in this order.

  The charging device 8 is a corona charging type charging device and charges the electrophotographic photoreceptor 7. Examples of the charging device 8 include a corotron charger and a scorotron charger. The charging device 8 is connected to a power source 9.

  The exposure device 10 exposes the charged electrophotographic photosensitive member 7 to form an electrostatic latent image on the electrophotographic photosensitive member 7.

  The developing device 11 develops the electrostatic latent image with a developer to form a toner image. The developer preferably contains toner particles having a volume average particle diameter of 3 to 9 μm obtained by a polymerization method.

  The transfer device 12 transfers the toner image developed on the electrophotographic photoreceptor 7 to a transfer medium.

  The cleaning device 13 removes toner remaining on the electrophotographic photosensitive member 7 after transfer. The cleaning device 13 preferably has a blade member that abuts against the electrophotographic photoreceptor 7 at a linear pressure of 10 to 150 g / cm.

  The static eliminator (erase device) 14 erases the remaining charges on the electrophotographic photosensitive member 7.

  In addition, the electrophotographic apparatus 100 includes a fixing device 15 that fixes a toner image on a transfer medium after the transfer process.

  FIG. 3 is a schematic view showing another preferred embodiment of the electrophotographic apparatus of the present invention. The electrophotographic apparatus 110 shown in FIG. 3 has the same configuration as the electrophotographic apparatus 100 shown in FIG. 2 except that it includes a charging device 8 that charges the electrophotographic photoreceptor 7 by a contact method. In particular, in the electrophotographic apparatus 110 that employs a contact-type charging device in which an AC voltage is superimposed on a DC voltage, the electrophotographic photoreceptor 7 can be preferably used because it has excellent leakage resistance. In this case, the static eliminator 14 may not be provided.

  In the contact charging method, charging members such as a roller shape, a blade shape, a belt shape, a brush shape, and a magnetic brush shape are applicable. In particular, the roller-like or blade-like charging member may be arranged in a contact state or a non-contact state having a certain amount of gaps (100 μm or less) with respect to the electrophotographic photoreceptor 7.

A roller-shaped charging member, a blade-shaped charging member, and a belt-shaped charging member are composed of a material adjusted to an effective electrical resistance (10 ³ Ω to 10 ⁸ Ω) as a charging member, You may be comprised from several layers.

  The material is mainly composed of synthetic rubber such as urethane rubber, silicon rubber, fluoro rubber, chloroprene rubber, butadiene rubber, EPDM, epichlorohydrin rubber, and elastomers such as polyolefin, polystyrene, vinyl chloride, conductive carbon, metal oxide. In addition, an appropriate electrical conductivity imparting agent such as an ionic conductive agent may be blended in an appropriate amount to develop an effective electrical resistance as a charging member.

  Furthermore, a resin such as nylon, polyester, polystyrene, polyurethane, silicone, etc. is made into a paint, and an appropriate amount of an optional conductivity imparting agent such as conductive carbon, metal oxide, or ionic conductive agent is blended therewith, and the resulting paint is dapped. It can be used by laminating by any method such as spraying or roll coating.

  On the other hand, for the brush-shaped charging member, a conventional fiber-impregnated fiber such as acrylic, nylon, polyester, etc., which has been used in the past, is impregnated with fluorine, and then implanted using a conventional method. Can be produced. Further, after various fibers are formed on the brush-shaped charging member, fluorine impregnation treatment may be performed.

  The brush-shaped charging member referred to here may be any of a roller-shaped charging member and a brushed charging member, and the shape thereof is not particularly limited. Furthermore, the magnetic brush-like charging member is a member in which ferrite having a magnetic force, magnetite, etc. are arranged radially on the outer periphery of a cylinder containing a multi-pole magnet. A brush is desirable.

  FIG. 4 is a schematic view showing another preferred embodiment of the electrophotographic apparatus of the present invention. The electrophotographic apparatus 200 is a tandem type intermediate transfer type electrophotographic apparatus, and includes four electrophotographic photosensitive members 201a to 201d (for example, 201a is yellow, 201b is magenta, 201c is cyan, and 201d is black) in a housing 220. Color images can be formed respectively) along the intermediate transfer belt 209 and arranged in parallel with each other.

  Conventionally, as a method for transferring a visible image onto a transfer paper such as paper, a transfer drum method for winding a transfer paper such as paper around a transfer drum and transferring the visible image on the photosensitive member to the transfer paper for each color, etc. It has been known. In this case, compared with the tandem intermediate transfer method, the transfer of the visible image from the photosensitive member to the intermediate transfer member required the intermediate transfer member to rotate a plurality of times. This is a promising transfer method in the future because it can transfer images from a plurality of photoconductors 201a to 201d by one rotation of 209 and can improve the transfer speed and can select a transfer medium as in the transfer drum method. .

  Here, the electrophotographic photoreceptors 201a to 201d mounted on the electrophotographic apparatus 200 are the same as the electrophotographic photoreceptor 7 respectively.

  Each of the electrophotographic photoreceptors 201a to 201d can be rotated in a predetermined direction (counterclockwise on the paper surface), and the charging rolls 202a to 202d, the developing devices 204a to 204d, and the primary transfer roll 210a along the rotation direction. To 210d and cleaning devices 215a to 215d are arranged. Each of the developing devices 204a to 204d can be supplied with toner of four colors, yellow, magenta, cyan, and black, stored in the toner cartridges 205a to 205d. Further, the primary transfer rolls 210a to 210d are in contact with the electrophotographic photosensitive members 201a to 201d via the intermediate transfer belt 209, respectively.

  Further, a laser light source (exposure device) 203 is disposed at a predetermined position in the housing 220. Laser light emitted from the laser light source 203 can be applied to the surfaces of the electrophotographic photosensitive members 201a to 201d after charging. Accordingly, charging, exposure, development, primary transfer, and cleaning are sequentially performed in the rotation process of the electrophotographic photosensitive members 201a to 201d, and the toner images of the respective colors are transferred onto the intermediate transfer belt 209 in an overlapping manner.

  The intermediate transfer belt 209 is supported with a predetermined tension by a drive roll 206, a backup roll 208, and a tension roll 207, and can rotate without causing deflection due to the rotation of these rolls. The secondary transfer roll 213 is disposed so as to contact the backup roll 208 via the intermediate transfer belt 209. The intermediate transfer belt 209 that has passed between the backup roll 208 and the secondary transfer roll 213 is cleaned by a cleaning blade 216 disposed in the vicinity of the drive roll 206, for example, and then repeatedly used for the next image forming process. Is done.

  Further, a tray (transfer medium tray) 211 is provided at a predetermined position in the housing 220, and the transfer medium 230 such as paper in the tray 211 is transferred by the transfer roll 212 to the intermediate transfer belt 209 and the secondary transfer roll. Then, the sheet is sequentially transferred between the two fixing rolls 214 that are in contact with each other and between the two fixing rolls 214 and then discharged to the outside of the housing 220.

  In the above description, the case where the intermediate transfer belt 209 is used as the intermediate transfer member has been described. However, the intermediate transfer member may have a belt shape (for example, an endless belt shape) like the intermediate transfer belt 209. It may be a drum shape. When a belt-shaped configuration such as the intermediate transfer belt 209 is adopted as the intermediate transfer member, generally the film thickness of the belt is preferably 50 to 500 μm, more preferably 60 to 150 μm. In addition, the film thickness of a belt can be suitably selected according to the hardness of material. When a drum-shaped configuration is adopted as the intermediate transfer member, it is preferable to use a cylindrical substrate formed of aluminum, stainless steel (SUS), copper, or the like as the substrate. If necessary, an elastic layer can be coated on the cylindrical substrate, and a surface layer can be formed on the elastic layer.

  The medium to be transferred in the present invention is not particularly limited as long as it is a medium for transferring a toner image formed in the shape of an electrophotographic photosensitive member. For example, when transferring directly from an electrophotographic photosensitive member to paper or the like, paper or the like is a transfer medium, and when an intermediate transfer member is used, the intermediate transfer member is a transfer medium.

  As the material of the endless belt, heat such as polycarbonate resin (PC), polyvinylidene fluoride (PVDF), polyalkylene phthalate, PC / polyalkylene phthalate (PAT) blend material, ethylene tetrafluoroethylene copolymer (ETFE), etc. A semiconductive endless belt made of a plastic resin has been proposed.

  Japanese Patent No. 2560727, Japanese Patent Application Laid-Open No. 5-77252, etc. propose an intermediate transfer member in which ordinary carbon black is dispersed as a conductive fine powder in a polyimide resin.

  Since the polyimide resin is a material having a high Young's modulus, it is less likely to be deformed by driving (stress of a support roll, a cleaning blade, etc.), so that it becomes an intermediate transfer body in which image defects such as color misregistration are unlikely to occur. A polyimide resin is usually obtained as a polyamic acid solution by polymerizing a substantially equimolar amount of tetracarboxylic dianhydride or its derivative and a diamine in a solvent. As tetracarboxylic dianhydride, what is shown by the following general formula (IV) is mentioned, for example.

[Wherein, R is a tetravalent group selected from the group consisting of an aliphatic chain hydrocarbon group, an aliphatic cyclic hydrocarbon group, an aromatic hydrocarbon group, and a group in which a substituent is bonded to these hydrocarbon groups. An organic group of ]

  Specific examples of the tetracarboxylic dianhydride include pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, and 3,3 ′, 4,4′-biphenyltetracarboxylic acid. Acid dianhydride, 2,3,3 ′, 4-biphenyltetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic acid Dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,2′-bis (3,4-dicarboxyphenyl) sulfonic dianhydride, perylene-3,4,9,10 -Tetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, ethylenetetracarboxylic dianhydride, etc. are mentioned.

On the other hand, specific examples of the diamine include 4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenylmethane, 3,3′-diaminodiphenylmethane, 3,3′-dichlorobenzidine, 4,4′-diaminodiphenyl sulfide, 3,3′-diaminodiphenylsulfone, 1,5-diaminonaphthalene, m-phenylenediamine, p-phenylenediamine, 3,3′-dimethyl-4,4′-biphenyldiamine, benzidine, 3,3′-dimethylbenzidine 3,3′-dimethoxybenzidine, 4,4′-diaminodiphenylsulfone, 4,4′-diaminodiphenylpropane, 2,4-bis (β-aminotert-butyl) toluene, bis (p-β-amino- Tert-butylphenyl) ether, bis (p-β-methyl-δ-aminophenyl) benzene, bis p- (1,1-dimethyl-5-amino-benzyl) benzene, 1-isopropyl-2,4-m-phenylenediamine, m-xylylenediamine, p-xylylenediamine, di (p-aminocyclohexyl) methane , Hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, diaminopropyltetramethylene, 3-methylheptamethylenediamine, 4,4-dimethylheptamethylenediamine, 2,11-diaminododecane, 1 , 2-bis-3-aminopropoxyethane, 2,2-dimethylpropylenediamine, 3-methoxyhexamethylenediamine, 2,5-dimethylheptamethylenediamine, 3-methylheptamethylenediamine, 5-methylnonamethylenediamine, 2 17-diaminoeicosadecane, 1,4-diaminocyclohexane, 1,10-diamino-1,10-dimethyldecane, 12-diaminooctadecane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, _{piperazine, H 2 N (CH 2)} 3O (CH 2) 2O (CH 2) NH 2, H 2 N (CH 2) 3 S (CH 2) 3 NH 2, H 2 N (CH 2) 3 N (CH ₃ ) ₂ (CH ₂ ) ₃ NH _{2 and the} like.

  As the solvent for the polymerization reaction of tetracarboxylic dianhydride and diamine, a polar solvent is preferably used from the viewpoint of solubility. As the polar solvent, N, N-dialkylamides are preferable, and specific examples thereof include N, N-dimethylformamide, N, N-dimethylacetamide, N, N-diethylformamide, which are low molecular weight compounds thereof. N, N-diethylacetamide, N, N-dimethylmethoxyacetamide, dimethyl sulfoxide, hexamethylphosphortriamide, N-methyl-2-pyrrolidone, pyridine, tetramethylenesulfone, dimethyltetramethylenesulfone and the like. These can be used alone or in combination of two or more.

  The intermediate transfer member contains oxidized carbon black in a polyimide resin. Oxidized carbon black can be obtained by oxidizing carbon black to give an oxygen-containing functional group (for example, carboxyl group, quinone group, lactone group, hydroxyl group, etc.) to the surface.

  This oxidation treatment is an air oxidation method in which contact is caused to react with air in a high temperature atmosphere, a method in which it reacts with nitrogen oxide or ozone at room temperature, and a method in which ozone oxidation is performed at low temperature after air oxidation at high temperature. Etc.

  Specific examples of the oxidized carbon include MA100 (pH 3.5, volatile matter 1.5%), MA100R (pH 3.5, volatile matter 1.5%), and MA100S (pH 3.5, volatile matter) manufactured by Mitsubishi Chemical. 1.5%), # 970 (pH 3.5, volatile content 3.0%), MA11 (pH 3.5, volatile content 2.0%), # 1000 (pH 3.5, volatile content 3.). 0%), # 2200 (pH 3.5, volatile content 3.5%), MA 230 (pH 3.0, volatile content 1.5%), MA 220 (pH 3.0, volatile content 1.0%), # 2650 (pH 3.0, volatile content 8.0%), MA7 (pH 3.0, volatile content 3.0%), MA8 (pH 3.0, volatile content 3.0%), OIL7B (pH 3) 0.0, volatile content 6.0%), MA77 (pH 2.5, volatile content 3.0%), # 2350 (pH) .5, volatile content 7.5%), # 2700 (pH 2.5, volatile content 10.0%), # 2400 (pH 2.5, volatile content 9.0%), Dexa Printex 150T (PH 4.5, volatile content 10.0%), Special Black 350 (pH 3.5, volatile content 2.2%), Special Black 100 (pH 3.3, volatile content 2.2%), Special Black 250 (pH 3.1, volatile content 2.0%), Special Black 5 (pH 3.0, volatile content 15.0%), Special Black 4 (pH 3.0, volatile content 14.0%), Special Black 4A (pH 3.0, volatile content 14.0%), Special Black 550 (pH 2.8, volatile content 2.5%), Special Black 6 (pH 2.5, volatile content 18.0%), Color black FW20 (PH 2.5, volatile content 20.0%), same color black FW2 (pH 2.5, volatile content 16.5%), same color black FW2V (pH 2.5, volatile content 16.5%), manufactured by Cabot Corporation MONARCH 1000 (pH 2.5, volatile content 9.5%), MONARCH 1300 (pH 2.5, volatile content 9.5%) manufactured by Cabot, MONARCH 1400 (pH 2.5, volatile content 9.0%) manufactured by Cabot, MOGUL -L (pH 2.5, volatile matter 5.0%), REGAL400R (pH 4.0, volatile matter 3.5%);

  The oxidation-treated carbon black obtained in this way has an excessive current flowing in part and is not easily affected by oxidation due to repeated voltage application. Furthermore, due to the effect of the oxygen-containing functional group attached to the surface, the dispersibility in polyimide is high, the resistance variation can be reduced, the electric field dependency is also reduced, and the electric field concentration due to the transfer voltage is less likely to occur. .

  As a result, resistance degradation due to transfer voltage is prevented, uniformity of electrical resistance is improved, electric field dependency is small, resistance change due to the environment is small, and image quality defects such as whitening of the paper running part occur. The intermediate transfer member can obtain a suppressed high image quality. If at least two types are included, these oxidized carbon blacks preferably have substantially different conductivity, such as the degree of oxidation treatment, DBP oil absorption, specific surface area by the BET method using nitrogen adsorption, etc. Use materials with different physical properties.

  When two or more types of carbon blacks having different physical properties are added as described above, for example, carbon black exhibiting high conductivity is preferentially added, and then carbon black having low conductivity is added to adjust the surface resistivity. It is possible.

  Specific examples of the oxidized carbon black include SPECIAL BLACK4 (Degussa, pH 3.0, volatile content: 14.0%), SPECIAL BLACK250 (Degussa, pH 3.1, volatile content: 2.0%), and the like. Is mentioned. The content of these oxidized carbon blacks is preferably about 10 to 50% by mass, more preferably 12 to 30% by mass with respect to the polyimide resin. If this content is less than 10% by mass, the uniformity of electrical resistance may be reduced, and the decrease in surface resistivity during durable use may increase. On the other hand, if it exceeds 50% by mass, the desired resistance value may be obtained. Is not preferred, and it is not preferable because it becomes brittle as a molded product.

  The intermediate transfer body made of polyimide resin in which oxidized carbon black is dispersed performs a step of preparing a polyamic acid solution in which oxidized carbon black is dispersed, a step of forming a film (layer) on the inner surface of a cylindrical mold, and imide conversion It can be obtained through a process.

  About the manufacturing method of the polyamic acid solution which disperse | distributed 2 or more types of oxidation treatment carbon black, the said acid dianhydride component and diamine component are contained in the dispersion liquid which disperse | distributed 2 or more types of oxidation treatment carbon black beforehand in the solvent. Method of dissolving and polymerizing Two or more types of oxidized carbon black are each dispersed in a solvent to prepare two or more types of carbon black dispersions, and the acid anhydride component and the diamine component are dissolved and polymerized in this dispersion. Thereafter, a method of mixing each polyamic acid solution, etc. can be considered, and a polyamic acid solution in which carbon black is dispersed is prepared by selecting as appropriate.

  The polyamic acid solution thus obtained is supplied to and spread on the inner surface of the cylindrical mold to form a film, and the polyamic acid is obtained by imide conversion by heating. In this heating step for imide conversion, an intermediate transfer member having good flatness can be obtained by performing imide conversion under heating conditions that are maintained at a constant temperature for 0.5 hour or more. This will be described in detail below.

  A polyamic acid solution is supplied to the inner surface of the cylindrical mold. This supply method can be performed by appropriately selecting a method using a dispenser, a method using a die, or the like. The surface state of the inner peripheral surface of the cylindrical mold used at this time is preferably mirror-finished.

  A coating film having a uniform film thickness is formed by appropriately selecting the polyamic acid solution supplied in this manner, such as a method of performing centrifugal molding while heating, a method of molding using a bullet-shaped traveling body, or a method of rotational molding. Subsequently, after heating the mold together with the mold with the coating formed on the inner peripheral surface in a dryer and raising the temperature until imide conversion, or after removing the solvent until the shape can be maintained as a belt, from the inner surface of the mold A method may be considered in which, after peeling and replacing the outer surface of a metal cylinder, the entire cylinder is heated to perform imide conversion. In order to obtain an intermediate transfer member having suitable flatness and outer surface accuracy, it is preferable to remove the solvent until it can be held as a belt, and then replace it with a metal cylinder to perform imide conversion.

  The heating conditions in the step of removing the solvent are not particularly limited as long as the removal of the solvent proceeds, but preferably at 80 to 200 ° C. for 0.5 to 5 hours. Next, the molded product that can retain its shape as a belt is peeled off from the inner peripheral surface of the mold. At this time, a mold release process can be performed on the inner peripheral surface of the mold.

  Next, the molded product heated and cured until it can be held as a belt shape is replaced with the outer surface of the metal cylinder, and the replaced cylinder is heated to advance the imide conversion reaction of the polyamic acid.

  The metal cylinder used at this time preferably has a linear expansion coefficient larger than that of the polyimide resin. By making the outer diameter of the cylinder smaller than the inner diameter of the polyimide molding by a predetermined amount, heat setting can be performed and a uniform film thickness can be obtained. Thus, an endless belt without unevenness can be obtained. The surface roughness (Ra) of the outer surface of the metal cylinder used at this time is preferably 1.2 to 2.0 μm. If the surface roughness (Ra) of the outer surface of the metal cylinder is smaller than 1.2 μm, the belt-shaped intermediate transfer member obtained because the metal cylinder itself is too smooth will not slip due to contraction in the axial direction of the belt. This is performed in this step, which causes variations in film thickness and a decrease in flatness accuracy.

  Also, if the surface roughness (Ra) of the outer surface of the metal cylinder is larger than 2.0 μm, the outer surface of the metal cylinder is transferred to the inner surface of the belt-shaped intermediate transfer member, and unevenness is generated on the outer surface, thereby causing image defects. generate. The surface roughness (Ra) of the outer surface of the belt-shaped intermediate transfer member made of polyimide resin in which carbon black thus obtained is dispersed is 1.5 μm or less.

  The surface roughness is measured according to JIS B601. When the surface roughness (Ra) of the intermediate transfer member is larger than 1.5 μm, image defects such as roughening occur. The reason for this is that when the voltage applied locally during transfer or the electric field due to the stripping discharge is concentrated on the convex part of the belt surface, the surface of this part is altered and a new conductive path is created, resulting in a decrease in resistance. However, the density is lowered, and it seems that the entire image looks cluttered.

  It is preferable that the heating process for imide conversion is performed at a heating temperature of 220 to 280 ° C. and a heating time of 0.5 to 2 hours. Although depending on the composition of the polyimide resin, the amount of shrinkage is the largest in this region under the heating conditions during imide conversion.Thus, by gently performing the shrinkage in the axial direction of the belt, film thickness variation and flatness A reduction in accuracy can be prevented.

  The intermediate transfer member that has undergone such a heating step has a flatness of 5 mm or less, preferably 3 mm or less. When the flatness is 5 mm or less, there is no roughness and color deviation is small. However, when the belt end is bent vertically, the intermediate transfer member will not break during use even if it is 5 mm or less, but it rarely remains after contacting the peripheral member. Further, when the flatness is 3 mm or less, the intermediate transfer member is not brought into contact with the peripheral member during use and there is almost no color shift.

(Process cartridge)
Next, a process cartridge equipped with an electrophotographic photosensitive member will be described.

FIG. 5 is a schematic view showing a preferred embodiment of the process cartridge according to the present invention.
In the process cartridge 300, a charging device 303, a developing device 307, a cleaning device 311, and a static eliminator 313 are combined in a case 301 together with an electrophotographic photosensitive member 301 using a mounting rail 303. The process cartridge 300 is not provided with an exposure device, but an opening 305 for exposure is formed in the case 301. The electrophotographic photoreceptor 301 is the above-described electrophotographic photoreceptor of the present invention, and has at least an undercoat layer and a photosensitive layer on the conductive substrate 1, and the undercoat layer is composed of an acceptor compound and a metal oxide. This is an electrophotographic photoreceptor 7 containing product particles.

  The process cartridge 300 is detachable from an electrophotographic apparatus main body including a transfer device 309, a fixing device 317, and other components not shown, and constitutes an electrophotographic apparatus together with the electrophotographic apparatus main body. To do.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples.

Example 1
Zinc oxide: (average particle diameter 70 nm: manufactured by Teika Co., Ltd .: specific surface area value 15 m ² / g) 100 parts by mass is stirred and mixed with 500 parts by mass of tetrahydrofuran, and silane coupling agent (KBM603: manufactured by Shin-Etsu Chemical Co., Ltd.) 1.25 mass Part was added and stirred for 2 hours. Thereafter, toluene was distilled off under reduced pressure and baked at 120 ° C. for 3 hours to obtain a silane coupling agent surface-treated zinc oxide pigment.

  60 parts by mass of the zinc oxide pigment subjected to the surface treatment, 0.6 parts by mass of alizarin and a curing agent Blocked isocyanate (Sumidule 3173: manufactured by Sumitomo Bayern Urethane Co., Ltd.) 13.5 parts by mass and a butyral resin (BM-1: (Manufactured by Sekisui Chemical Co., Ltd.) 38 parts by mass of a solution obtained by dissolving 15 parts by mass in 85 parts by mass of methyl ethyl ketone and 25 parts by mass of methyl ethyl ketone were mixed, and dispersed for 2 hours with a sand mill using 1 mmφ glass beads to obtain a dispersion. It was. As a catalyst, 0.005 part by mass of dioctyltin dilaurate and 4.0 parts by mass of silicone resin particles (Tospearl 145: manufactured by GE Toshiba Silicone) were added to the resulting dispersion to obtain a coating solution for undercoat layer. This coating solution was applied onto an aluminum substrate by a dip coating method, followed by drying and curing at 170 ° C. for 40 minutes to obtain an undercoat layer having a thickness of 25 μm.

  Next, a photosensitive layer was formed on the undercoat layer. First, X-ray diffraction spectrum Bragg angles (2θ ± 0.2 °) using Cukα as a charge generating material are at least 7.3 °, 16.0 °, 24.9 °, and 28.0 °. A mixture consisting of 15 parts by mass of hydroxygallium phthalocyanine having a diffraction peak, 10 parts by mass of vinyl chloride-vinyl acetate copolymer resin (VMCH, manufactured by Nihon Unicar) as a binder resin, and 200 parts by mass of n-butyl acetate, Dispersion was carried out for 4 hours in a sand mill using glass beads of 1 mmΦ. To the obtained dispersion liquid, 175 parts by mass of n-butyl acetate and 180 parts by mass of methyl ethyl ketone were added and stirred to obtain a coating solution for a charge generation layer. This charge generation layer coating solution was dip coated on the undercoat layer and dried at room temperature to form a charge generation layer 31 having a thickness of 0.2 μm.

Next, 1 part by mass of tetrafluoroethylene resin particles, 0.02 part by mass of the fluorine-based graft polymer, 5 parts by mass of tetrahydrofuran, and 2 parts by mass of toluene were sufficiently stirred and mixed to obtain a tetrafluoroethylene resin particle suspension. . Next, 4 parts by mass of N, N′-diphenyl-N, N′-bis (3-methylphenyl)-[1,1 ′] biphenyl-4,4′-diamine, a bisphenol Z-type polycarbonate resin ( Viscosity average molecular weight 40,000) 6 parts by mass, 23 parts by mass of tetrahydrofuran and 10 parts by mass of toluene are mixed and dissolved, and the tetrafluoroethylene resin particle suspension is added and mixed by stirring. Using a high-pressure homogenizer (trade name LA-33S, manufactured by Nanomizer Co., Ltd.) equipped with a pressure chamber, the dispersion treatment with the pressure increased to 400 kgf / cm ² (3.92 × 10 ⁻¹ Pa) was repeated 6 times. An ethylene resin particle dispersion was obtained. Further, 0.2 parts by mass of 2,6-di-t-butyl-4-methylphenol was mixed to obtain a coating solution for forming a charge transport layer. This coating solution was applied onto the charge generation layer 31 and dried at 115 ° C. for 40 minutes to form a charge transport layer having a thickness of 32 μm, thereby obtaining an electrophotographic photosensitive member.

  The electrophotographic photoreceptor thus obtained is mounted on a full-color printer DocuCenter Color C400 manufactured by Fuji Xerox Co., Ltd. having a contact charging device and an intermediate transfer device, and is initially and under high temperature and high humidity (28 ° C. and 40% RH). As a result of examining the continuous print quality of 10,000 sheets, a good image quality without ghosting and fog / black spots was obtained. In addition, it showed excellent maintainability with no black spots due to leak defects. The results are shown in Table 11.

(Examples 2 to 4)
An electrophotographic photoreceptor was formed in the same manner as in Example 1 except that the metal oxide surface-treated with the silane coupling agent and the acceptor compound in Example 1 were changed to the substances shown in Table 1, and the characteristics were evaluated. The results are shown in Table 11.

(Comparative Example 1)
An electrophotographic photosensitive member was formed in the same manner as in Example 1 except that no acceptor compound was used in Example 1, and the characteristics were evaluated. The results are shown in Table 11.

1 is a schematic cross-sectional view showing an example of an electrophotographic photoreceptor according to the present invention. 1 is a schematic diagram showing a preferred embodiment of an electrophotographic apparatus according to the present invention. It is a schematic diagram which shows other suitable embodiment of the electrophotographic apparatus which concerns on this invention. It is a schematic diagram which shows other suitable embodiment of the electrophotographic apparatus which concerns on this invention. It is a schematic diagram showing a preferred embodiment of a process cartridge according to the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Conductive substrate, 2 ... Intermediate layer, 3 ... Photosensitive layer, 31 ... Charge generation layer, 32 ... Charge transport layer, 5 ... Protective layer, 7 ... Electrophotographic photosensitive member, 8 ... Charging device, 10 ... Exposure device, DESCRIPTION OF SYMBOLS 11 ... Developer, 12 ... Transfer device, 13 ... Cleaning device, 100,110,200, ... Electrophotographic device, 209 ... Intermediate transfer member, 300 ... Process cartridge

Claims (10)

An electrophotographic photoreceptor having at least an undercoat layer and a photosensitive layer on a conductive substrate, wherein the undercoat layer has an anthraquinone structure having a metal oxide fine particle and a group capable of reacting with the metal oxide fine particle; An electrophotographic photosensitive member comprising:   2. The electrophotographic photoreceptor according to claim 1, wherein the group capable of reacting with the metal oxide fine particles of the acceptor compound is a hydroxyl group. The electrophotographic photoreceptor according to claim 1 or 2, wherein the acceptor compound is selected from a hydroxyanthraquinone compound and an aminohydroxyanthraquinone compound . The electrophotographic photoreceptor according to claim 3, wherein the hydroxyanthraquinone compound is selected from alizarin, 1-hydroxyanthraquinone, and purpurin. The electrophotographic photosensitive member according to any one of claims 1 to 4 , wherein the metal oxide fine particles are surface-treated with a coupling agent. The electrophotographic photosensitive member according to any one of claims 1 to 5 , wherein the outermost surface of the electrophotographic photosensitive member contains fluorine-based resin particles. An electrophotographic photosensitive member according to any one of claims 1 to 6 , and at least one of a charging device, a developing device, a cleaning device, and a static eliminator, and can be freely attached to and detached from an electrophotographic apparatus main body. A process cartridge characterized by being. An electrophotographic apparatus using the electrophotographic photosensitive member according to any one of claims 1 to 6 . 9. The electrophotographic apparatus according to claim 8 , further comprising a contact-type charging device that contacts the photoconductor to charge the photoconductor. 9. The electrophotographic apparatus according to claim 8 , further comprising an intermediate transfer device that transfers an image formed on the electrophotographic photosensitive member.

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